Barrier Coating and Paint over Transducer Tube Bottoms

[John Nardi]

Hi Guys....My bottom is stripped and blisters faired and soon I will build the new bottom with Barrier Kote and Bottom Paint...My boat came with the glycerin filled tubes that house the transducers for 2KW Xducers....If they weren't so powerful and functional, I would change them out, but the match up with the Navnet that I plan to use perfectly...I have never had these before and figured I would ask if there is any special prep and/or paint technique that one needs to consider as the beams are shot through the hull...Thanks, John

[Navatech]

I would ask if there is any special prep and/or paint technique that one needs to consider as the beams are shot through the hull...Thanks, John

Absolutely nothing... These transducers will shoot through your barrier coat and (standard) antifouling just as easily as they shoot through the hull... If you're going for some fancy shmancy antifouling (e.g. CopperCoat) I suggest you check with them but I'd be amazed if it would be a problem...

As a word of advice, do your first coat of antifouling in one color (say red), then do the other 1.5-2.5 coats in the color that you want (say black)... That way you'll have a telltale when it's time to redo your antifouling... I.e. when the red coat starts showing through the black coats...

[Yannis]

Relevant to anti fouling:

The practice here is that you get 2 layers of new anti fouling each time.
In other words, when the boat is ready to splash you fair your old anti fouling to create a bonding surface and apply 2 layers of new anti fouling. I don't understand why one would start playing around with anti fouling colors if anti fouling is applied EVERY year. Unless over in the US you do NOT apply anti fouling every year; but then again, when you pull the boat out for ANY period, short or long, your anti fouling dies, so you need a new one anyway. Beats me .....
As also beats me, why nobody considers "copper cote" as a permanent solution against seasonal anti fouling applications. Done once - done for 5+ years..., then a simple fairing,1 or 2 new coats and off you go for another 5+ years.

[Tony Meola]

Relevant to anti fouling:

The practice here is that you get 2 layers of new anti fouling each time.
In other words, when the boat is ready to splash you fair your old anti fouling to create a bonding surface and apply 2 layers of new anti fouling. I don't understand why one would start playing around with anti fouling colors if anti fouling is applied EVERY year. Unless over in the US you do NOT apply anti fouling every year; but then again, when you pull the boat out for ANY period, short or long, your anti fouling dies, so you need a new one anyway. Beats me .....
As also beats me, why nobody considers "copper cote" as a permanent solution against seasonal anti fouling applications. Done once - done for 5+ years..., then a simple fairing,1 or 2 new coats and off you go for another 5+ years.

Yannis

In todays world, a lot of us use an ablative paint so there is no need to put it on every year. You can pull the boat and it does not go bad. One quick run and a layer dissolves off and it is as good as new, until it wears down to the point you need to recoat. That is the reason for the first coat to be a different color. Whe you see red re-paint. Actually in my case, when the bottom looks burnt. I put on red and then blue. When the red starts to show through the bottom looks like it burnt from electrolysis. But actually it is the red showing through the blue.

[Navatech]

I don't understand why one would start playing around with anti fouling colors if anti fouling is applied EVERY year.

First, many (most?) people in the US use ablative antifouling... As you move through the water a layer is "peeled" off and you have a (once again) a clean bottom... A big factor in this is how often a boat is actually used... Another big factor is the water temp... Higher water temp == more growth... Down here in the south (tropical/subtropical regions) it's not uncommon for boats to get hauled every 6 months for a cleanup and refreshing (1.5 or 2.5 layers) of the antifouling...

As also beats me, why nobody considers "copper cote" as a permanent solution against seasonal anti fouling applications. Done once - done for 5+ years..., then a simple fairing,1 or 2 new coats and off you go for another 5+ years.

I'm not sure... I'd guess it's a matter of cost and availability... Personally, I was going to try the ultrasonic units... Back in the navy we had good experience with those... By the way, why do you say 5 years for CopperCoat?!... Their web site claims more along the lines of 10 years...

[Yannis]

In todays world, a lot of us use an ablative paint

That explains it !!!
Over here, where boats are used for cruising and swimming and not necessarily (or never) for fishing, people swim around the boats to get to the ladder and get all blue or black with that poison; hence very few use ablative antifouling.

By the way, why do you say 5 years for CopperCoat?!... Their web site claims more along the lines of 10 years...

Just to be on the safe side!
As I have said here before, I have SEEN with my very eyes a sailboat that has spent 5 consecutive years in the water come out and be like a baby's bottom. My friend who owned it says that it's good practice every 5 or so years to pass a 400 grit and a couple of layers so that it remains like a baby's bottom for another 5 years or so.
Now, I know that the company claims 10 years right away, but I said 5 because I can confirm 5. At least 5. Voila !